JP5702539B2 - Hollow fiber membrane module - Google Patents

Description

  The present invention relates to a hollow fiber membrane module which is used for hemodialysis and water treatment and is modularized by housing a bundle of hollow fiber membranes, which are dialysis membranes, in a cylindrical housing, that is, as an independent replacement part.

  In hemodialysis, waste and excess water in the blood are discharged into the dialysate through the dialysis membrane, and the electrolyte in the dialysate is sent into the blood through the dialysis membrane. Since a dialysis membrane once used for hemodialysis is prohibited from being used again for hygiene reasons, the dialysis membrane is frequently replaced. Here, when a dialysis patient suffers from some kind of disease, the causative substance of the disease may adhere to the dialysis membrane after use. Contact with the membrane must be avoided. Therefore, in order to easily and safely exchange the dialysis membrane, conventionally, a dialysis membrane module is used which is modularized by accommodating the dialysis membrane in a container called a housing, that is, an independent replacement part. When exchanging the dialysis membrane, the entire dialysis membrane module is exchanged so that the operator can avoid touching the dialysis membrane after use.

  In the dialysis membrane module, sheet-like dialysis membranes are laminated, and blood is flown through the inside of a hollow fiber membrane, which is a straw-type dialysis membrane, in which blood and dialysate are alternately flowed between the layers. A hollow fiber membrane module that allows dialysate to flow outside the yarn membrane is known. Among these, the hollow fiber membrane module is known to have higher dialysis efficiency than the laminated module, and has been rapidly spread in recent years.

  Further, the hollow fiber membrane module is used as a purification filter for purifying drinking water and industrial water in addition to the above-described hemodialysis.

  The hollow fiber membrane module includes a housing having a cylindrical shape with both ends opened, a hollow fiber membrane bundle accommodated in the housing, and a flow passage fixed to the outer peripheral surface of both ends of the housing and provided with a liquid passage port. And a liquid cap. In the case of the type for hemodialysis, a dialysate supply port and a discharge port are provided, and these are provided on the cylindrical wall of the housing or the liquid passing cap. Similarly, in the case of a type that performs water treatment, a concentrated water discharge port (also a raw water supply port in some cases) is provided on the cylindrical wall of the housing, or the concentrated water discharge port and the raw water supply port are passed through. Some are provided on the liquid cap.

  In the housing, there is a sealing member called a potting material that fixes the end of the hollow fiber membrane bundle accommodated in the housing and seals the housing so that dialysate and concentrated water do not leak from the housing. Is provided. The sealing member is made of a thermosetting resin such as polyurethane, phenol resin, or epoxy resin, fills a gap between the end portions of the hollow fiber membrane, and is fixed to inner peripheral surfaces of both end portions of the housing.

The hollow fiber membrane module is manufactured through the following steps.
(1) The hollow fiber membrane bundle is accommodated in the housing.
(2) Fix sealing caps on the outer peripheral surfaces of both ends of the housing. Here, the sealing cap is a member different from the liquid passing cap, and a hole such as a liquid passing port is not opened. By fixing the sealing cap, both ends of the housing are sealed.
(3) A viscous liquid sealing member is injected from the dialysate supply port and the discharge port (or the raw water supply port and the concentrated water discharge port) of the housing. After the injection, the housing is rotated around a rotation axis that is the center in the axial direction of the housing and is perpendicular to the axial direction, and the sealing member is brought close to both ends of the housing by centrifugal force. At this time, the sealing member is filled in the gap at the end of the hollow fiber membrane.
(4) The sealing member is cured by heating the sealing member. Thereby, the hollow fiber membrane bundle is fixed to the sealing member, and the sealing member is fixed to the inner peripheral surfaces of both ends of the housing.
(5) Remove the sealing cap and fix the liquid passing cap to the outer peripheral surfaces of both ends of the housing.
(6) The assembled hollow fiber membrane module is sterilized.

  Here, heat sterilization is conventionally performed as the sterilization treatment of (6) above. When the hollow fiber membrane module is used for water treatment, in addition to the sterilization treatment, heat sterilization with hot water or the like is periodically performed between water treatments. For example, in Patent Document 1, heat sterilization is performed by supplying a heating fluid such as hot water into a housing from a liquid inlet of a liquid cap.

JP-A-9-220445

  In the heat sterilization process described above, the sealing member is thermally expanded by supplying the heating fluid into the housing. On the other hand, since the sealing member is fixed to the inner peripheral surface of the housing, expansion of the sealing member is restricted by the housing. As a result, stress (thermal stress) is generated in the sealing member, and the sealing member presses the inner peripheral surface of the housing. The housing pressed by the sealing member tends to bend outward. Here, since the liquid passing caps are fixed to the outer peripheral surfaces of both ends of the housing, the bending of the both ends of the housing to the outer peripheral side is restricted. As a result, a compressive load is applied to the cylindrical walls at both ends of the housing, and if this compressive load exceeds the load limit of the cylindrical wall, cracks called cracks may occur on the cylindrical wall.

  On the other hand, when viewed from the liquid passing cap side, the housing is going to bend toward the outer peripheral side, so that a tensile load is applied to the liquid passing cap. When the load limit of the liquid passing cap is smaller than the load limit of the housing, a crack occurs in the liquid passing cap.

  Then, an object of this invention is to provide the hollow fiber membrane module provided with the mechanism which absorbs the load concerning a housing both ends.

  The invention according to claim 1 is characterized in that the hollow fiber membrane bundle is formed by filling a gap between the cylindrical housing having an open end, the hollow fiber membrane bundle accommodated in the housing, and the end of the hollow fiber membrane. A hollow fiber membrane module comprising: a sealing member fixed to both ends of the housing; and a liquid-permeable cap fixed to both ends of the housing and provided with a liquid-permeable port. The both end portions of the housing have a double cylinder structure of an inner cylinder and an outer cylinder, the sealing member is fixed to the inner cylinder, and the liquid passing cap is fixed to the outer peripheral surface of the outer cylinder. And the stress by the thermal expansion of the said sealing member is absorbed by the clearance gap formed between the said inner cylinder and the said outer cylinder.

  The invention according to claim 2 is the hollow fiber membrane module according to claim 1, wherein the sealing member is fixed to an inner peripheral surface of the inner cylinder.

The invention according to claim 3 is the hollow fiber membrane module according to claim 1, wherein the sealing member is fixed so that an end portion of the inner cylinder is buried in the sealing member, and the sealing member is sealed. The stress is absorbed by a gap between the outer peripheral surface of the stopper member and the inner peripheral surface of the outer cylinder.

  The invention according to claim 4 is the hollow fiber membrane module according to any one of claims 1 to 3, wherein the outer periphery of the gap is fixed from the end surface of the housing by the liquid-permeable cap. It is characterized by being formed up to the region depth.

  According to the first aspect of the present invention, both ends of the conventional housing are formed in a double cylinder structure of an inner cylinder and an outer cylinder, and the inner cylinder is configured to receive stress from the sealing member. A gap is formed between the inner cylinder and the outer cylinder, and when the inner cylinder receives stress from the sealing member, the inner cylinder is bent toward the outer peripheral side to absorb the stress. By providing a mechanism for absorbing stress, it is possible to prevent the occurrence of cracks at both ends of the housing or the liquid-permeable cap.

It is sectional drawing of the hollow fiber membrane module which concerns on this embodiment. It is the figure which expanded a part of hollow fiber membrane module which concerns on this embodiment. It is a perspective view of the housing which is a structural member of a hollow fiber membrane module. It is a perspective view of the housing which is a structural member of a hollow fiber membrane module. It is the figure which expanded a part of hollow fiber membrane module when a hollow fiber membrane module is heated. It is sectional drawing of the hollow fiber membrane module which concerns on another embodiment. It is sectional drawing of the hollow fiber membrane module which concerns on another embodiment. It is sectional drawing of the hollow fiber membrane module which concerns on another embodiment.

  First, the structure of the hollow fiber membrane module which concerns on this embodiment is demonstrated. FIG. 1 shows a cross-sectional view of a hollow fiber membrane module 1 according to the present embodiment.

  The hollow fiber membrane module 1 has a cylindrical shape and includes a housing 2 that is open at both ends. The housing 2 is made of a resin material such as polysulfone or polycarbonate. In addition, liquid passing caps 3 and 4 are provided at both ends of the housing 2 to seal both ends of the housing. When the hollow fiber membrane module 1 is used for hemodialysis, the fluid inlet 5 of the fluid cap 3 is connected to the artery side circuit of the hemodialyzer (not shown), and the fluid cap 4 is fluidized. The mouth 6 is connected to the venous circuit of the hemodialyzer. The tubular wall 7 of the housing 2 is provided with a dialysate supply port 8 and a dialysate discharge port 9. When the hollow fiber membrane module 1 is used for water treatment, the liquid inlet 5 of the liquid cap 3 is connected to the raw water supply pipe, and the liquid inlet 6 of the liquid cap 4 is connected to the purified water supply pipe. Connected. Further, a concentrated water discharge port is provided in the cylindrical wall 7 of the housing 2.

  Further, a hollow fiber membrane bundle 10 is accommodated in the housing 2, and a sealing member 11 that fixes the hollow fiber membrane bundle 10 and seals the housing 2 is fixed to inner peripheral surfaces of both ends of the housing 2. Yes. Further, an O-ring 12 made of an elastic body is sandwiched between the liquid passing caps 3 and 4 and the sealing member 11.

The sealing member 11 is also called a potting material, and is made of a thermosetting resin such as polyurethane, phenol resin, or epoxy resin. The sealing member 11 fixes the hollow fiber membrane bundle 10 by filling the gap between the hollow fiber membranes, and is fixed to the inner peripheral surfaces of both ends of the housing 2. Moreover, the linear expansion coefficient of the sealing member 11 is 10-20 [K < ^-1 >], and a volume expand | swells by heating. The linear expansion coefficient of the sealing member 11 is higher than the linear expansion coefficient of the housing 2, and the volume expansion ratio is larger in the sealing member 11.

  The enlarged view of the edge part of the hollow fiber membrane module 1 is shown in FIG. The cylinder wall 7 at both ends of the housing 2 has a double cylinder structure including an inner cylinder 16 and an outer cylinder 18. Further, a gap 13 is formed between the inner cylinder 16 and the outer cylinder 18. The gap 13 is cut along the axial direction of the housing 2 from the end surfaces 14 at both ends of the housing 2, and the depth thereof is a region where at least the outer periphery of the housing 2 is fixed by the liquid passing caps 3 and 4. The depth reaches L. For example, when a thread groove is provided in the liquid-permeable caps 3 and 4 and the housing 2 and they are fixed by screwing together, the depth of the gap 13 is the width of the thread groove region 15 provided on the outer peripheral surface of the housing 2 Is almost equal to When the liquid-permeable caps 3 and 4 and the housing 2 are fixed by ultrasonic welding, the depth of the gap 13 is substantially equal to the width of the welding surface provided on the outer peripheral surface of the housing 2. Specifically, the region depth L of the gap 13 is 5-50 mm, and the width T is 1-10 mm.

  The sealing member 11 is fixed to the inner peripheral surface of the inner cylinder 16, and when the thermal stress is generated in the sealing member 11, the inner cylinder 16 is pressed to the outer peripheral side. At this time, the inner cylinder 16 can bend toward the outer periphery side by the width T of the gap 13. The thermal stress of the sealing member 11 is absorbed by the inner cylinder 16 being bent toward the outer peripheral side. Since the thermal stress is absorbed, both ends of the housing 2 do not need to receive a compressive load. As a result, the generation of cracks due to the compressive load can be prevented. Further, since the thermal stress is absorbed, both end portions of the housing 2 do not press the liquid passing caps 3 and 4 toward the outer peripheral side. Therefore, since no tensile load is applied to the liquid passing caps 3 and 4, the occurrence of cracks in the liquid passing caps 3 and 4 can be prevented.

  In addition, the thickness of the inner cylinder 16 has sufficient thickness so that it may not break when bent to the outer peripheral side. Preferably, the inner cylinder 16 is preferably configured to have a thickness of 1-5 mm.

  The gap 13 may be formed over the entire circumference of the cylindrical wall 7 of the housing 2 as shown in FIG. 3, or may be intermittently formed in the cylindrical wall 7 as shown in FIG. In the latter case, the interval 17 between the adjacent gaps 13 is sufficiently short so that the housing 2 is not cracked by the thermal stress of the sealing member 11. Specifically, the interval 17 between the adjacent gaps 13 is configured to be 1 to 5 mm.

  The configuration of the hollow fiber membrane module 1 according to this embodiment has been described above. Next, the process for heating the hollow fiber membrane module 1 will be described.

  After assembling the hollow fiber membrane module 1 from the above-described components such as the housing 2 and the hollow fiber membrane bundle 10, the hollow fiber membrane module 1 is heat sterilized. In addition, when the hollow fiber membrane module 1 is used for water treatment, heat sterilization is also periodically performed between water treatments. Specifically, a high temperature sterilizing liquid such as hot water of 80 to 90 ° C. or a heated citric acid solution is supplied from the liquid flow port 5 of the liquid flow cap 3. The high temperature liquid introduced from the liquid flow cap 3 flows into the hollow fiber membrane bundle 10, and a part of the high temperature liquid reaches the liquid flow cap 4 and is discharged from the liquid flow port 6. The other part is filtered from the hollow fiber membrane and oozes out of the hollow fiber membrane, filling the housing 2. The high-temperature liquid that has leached into the housing 2 is discharged from the dialysate supply port 8 or the dialysate discharge port 9 of the housing 2 (from the concentrated water discharge port when a hollow fiber membrane module is used for water treatment). The

  In some cases, high-pressure steam sterilization is performed instead of supplying a high-temperature sterilizing solution. Furthermore, the hollow fiber membrane module 1 is heated not only in the sterilization step, but when the water to be treated in water treatment or the like is hot water, the hollow fiber membrane module 1 is heated during the water treatment. become. In such a heating state, the sealing member 11 is heated and expanded by the high-temperature fluid, and accordingly, thermal stress is generated in the sealing member 11. At this time, the inner cylinder 16 is pressed in the outer peripheral direction by the sealing member 11 at both ends of the housing 2. In response to this pressing, the inner cylinder 16 bends to the outer peripheral side as shown in FIG. When the inner cylinder 16 is bent, the thermal stress of the sealing member 11 is absorbed. Since the thermal stress is absorbed, both ends of the housing 2 do not need to receive a compressive load. Moreover, since both ends of the housing 2 do not press the liquid passing caps 3 and 4 to the outer periphery by absorbing the thermal stress, the liquid passing caps 3 and 4 do not need to receive a tensile load. Therefore, it is possible to prevent the occurrence of cracks due to compressive load or tensile load. Further, as described above, the depth of the gap 13 reaches at least from the end faces 14 at both ends of the housing 2 to the depth of the region where the outer periphery is fixed by the liquid passing caps 3 and 4. A gap 13 is formed over the entire area where a compressive load may be applied at both ends. Therefore, the occurrence of cracks can be prevented over the entire region at both ends of the housing 2.

  The hollow fiber membrane module according to this embodiment has been described above. In addition, the shape of the clearance gap 13 is not restricted to the form shown to FIGS. For example, the gap 13 may be provided so as to be inclined at a predetermined angle with respect to the axial direction of the housing 2 without providing the gap 13 in parallel with the axial direction of the housing 2. Further, the cross-sectional shape of the gap 13 may be substantially V-shaped, and the width T may be reduced in the depth direction.

  Furthermore, as shown in FIG. 6, the inner cylinder 16 is made lower than the outer cylinder 18 and the end of the inner cylinder 16 is buried in the sealing member 11. You may adhere the sealing member 11 over a side surface, an upper end surface, and an outer surface. As a result, the fixing area between the sealing member 11 and the inner cylinder 16 is increased, so that the peeling of the sealing member 11 from the inner cylinder 16 can be reliably prevented. In this configuration, a gap 19 is provided between the outer peripheral surface of the sealing member 11 and the inner surface of the outer cylinder 18. When the sealing member 11 is heated and expanded, the inner cylinder 16 is bent in the outer peripheral direction by the width of the gap 19, so that it is possible to avoid cracks at both ends of the housing 2 due to the thermal stress of the sealing member 11.

  In order to form the gap 19 between the outer peripheral surface of the sealing member 11 and the outer cylinder 18, an annular jig having a width of the gap 19 is previously attached to the outer cylinder 18, and then the sealing member 11 may be fixed to the inner peripheral surface of the housing 2. The sealing member 11 is introduced into the housing 2 in a viscous liquid state, and is heated and cured after filling the gaps in the hollow fiber membrane. After the annular jig described above is mounted on the outer cylinder 18, the viscous liquid sealing member 11 is introduced into the housing 2, and after the sealing member 11 is hardened, the jig is removed from the housing 2. A gap 19 is formed between the outermost peripheral surface of the sealing member 11 and the outer cylinder 18.

  In addition, this invention is not restricted to embodiment mentioned above, It can apply also to various hollow fiber membrane modules. For example, as shown in FIG. 7, the present invention can be applied to a hollow fiber membrane module in which a supply port and a discharge port are provided in the liquid passing caps 3 and 4 instead of providing a supply port and a discharge port in the housing 2. is there. In the hollow fiber membrane module 1 shown in FIG. 7, a first port 20 serving as a supply port or a discharge port is formed at the central portion of the liquid passing caps 3, 4, and the discharge port or the peripheral portion of the liquid passing caps 3, 4 is formed. A second port 21 serving as a supply port is formed. Further, a through-hole 22 is provided in the cylinder wall of the inner cylinder 16, and when the second port is used as an outlet, the fluid flows from the housing 2 to the inner cylinder 16 as shown by an arrow in FIG. 8. It is discharged through the path of the through hole 22 → the gap between the inner cylinder 16 and the outer cylinder 18 → the second port 21. The sealing member 11 is fixed to the inner cylinder 16 at a distance from the outer cylinder 18 so as not to block this path. Further, when the sealing member 11 is fixed to the inner cylinder 16, it is not fixed to the entire length in the axial direction of the inner cylinder 16, but is fixed to a region closer to the end portion of the housing 2 than the through hole 22 of the inner cylinder. Like that. In order to fix the sealing member 11 in this way, it is preferable to provide a projection that fits the through hole 22 on the inner peripheral side of the above-described annular jig. If the sealing member 11 is fixed to the inner cylinder 16 after the through-hole 22 is previously closed by the projection, the through-hole 22 can be prevented from being blocked by the sealing member 11.

  DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane module, 2 Housing, 3 Arterial side fluid cap, 4 Vein side fluid cap, 5 Arterial side fluid port, 6, Venous side fluid port, 7 Cylinder wall, 8 Dialysate supply port, 9 Dialysis Liquid discharge port, 10 hollow fiber membrane bundle, 11 sealing member, 12 O-ring, 13 gap, 14 housing end face, 15 thread groove region, 16 inner cylinder, 18 outer cylinder, 19 outermost peripheral surface and outside of sealing member 11 A gap with the cylinder, 20 first port, 21 second port, 22 through-hole.

Claims (4)

A cylindrical housing with an open end;
A hollow fiber membrane bundle accommodated in the housing;
Fixing the end of the hollow fiber membrane bundle by filling a gap between the ends of the hollow fiber membrane, and a sealing member fixed to both ends of the housing;
A liquid-permeable cap fixed to both ends of the housing and provided with a liquid-permeable port;
A hollow fiber membrane module comprising:
Both end portions of the housing have a double cylinder structure of an inner cylinder and an outer cylinder as part of a single cylinder wall, the sealing member is fixed to the inner cylinder, and the liquid passing cap is an outer periphery of the outer cylinder. Fixed to the surface, the stress due to thermal expansion of the sealing member is absorbed by narrowing the gap formed between the inner cylinder and the outer cylinder ,
A hollow fiber membrane module comprising an O-ring that is disposed on an inner peripheral side of the gap and is sandwiched between the liquid-permeable cap and the sealing member . The hollow fiber membrane module according to claim 1, wherein
The hollow fiber membrane module, wherein the sealing member is fixed to an inner peripheral surface of the inner cylinder . The hollow fiber membrane module according to claim 1, wherein
The sealing member is fixed so that an end portion of the inner cylinder is buried in the sealing member, and the sealing member
The hollow fiber membrane module, wherein the stress is absorbed by a gap between an outer peripheral surface of a member and an inner peripheral surface of the outer cylinder . The hollow fiber membrane module according to any one of claims 1 to 3 ,
The gap is a region where the outer periphery is fixed by the liquid passing cap from the end surface of the housing.
A hollow fiber membrane module characterized by being formed to a depth .

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